1 Get started

We will again use the penguins data included in R.

As always, before you get started with the exercise, make sure that you load the tidyverse

library(tidyverse)

2 Compare the flipper length of penguins using statistical tests

Question: Does the mean flipper length differ between the 3 penguin species?

Do separate comparisons for

• Gentoo vs. Adelie
• Gentoo vs. Chinstrap
• Adelie vs. Chinstrap

Before you start, create a subset of each species as a vector.

For this, you can use the $ operator:

adelie <- filter(penguins, species == "Adelie")$flipper_len
chinstrap <- filter(penguins, species == "Chinstrap")$flipper_len
gentoo <- filter(penguins, species == "Gentoo")$flipper_len

Follow the decision tree for statistical tests:

3 Extra

Create a plot to show the results of your tests. Choose one of the following:

• Create a boxplot with notches to visually compare differences in flipper length between species
• Make a plot showing the mean and standard error of the mean as pointrange or point with errorbars

Add a geom_signif() layer to the plot you just created to indicate your test results